FAQ - How do I bypass the iD22 mic preamps?

Tom Waterman

September 03, 2015 14:59

Updated

Can I bypass the Mic Pres on the iD22 (and use my own mic pres)?

You can easily bypass the mic pres on iD22 by simply patching the output of your other mic preamps or gear into the insert return, which is a very pure differential line stage into the ADC, therefore completely bypassing the on-board mic pres / HPF and line input stage.

This would allow you to still use the excellent Audient mic preamps for other duties in the analogue domain (output available at the insert send jack).

Hi Chris, thanks for your question. You do not need to configure anything in the matrix for input sources. Connect the outputs of your analogue mixer to the ADC insert returns on iD22. These will take balanced line level signals and route them directly from the ADC to the USB input channels 1 & 2.

Create a track in Logic assigned inputs 1&2 and you should be good to go!

Hi again Jon, no that is not possible because there are only two channels of AD converter. The iD22 preamps still function in the analogue domain and are available as an analogue signal at the insert send, but connecting an external mic pre to insert return will overide the iD internal mic pres at the ADC.

I'm strongly considering the iD22 as my next audio interface. I am also thinking about adding outboard gear options for mixing down the line, but I have no hands-on experience with that kind of setup so I have a few rudimentary questions that I hope you don't mind answering. These questions pertain to having already recorded audio in the digital domain, and using the iD22 to send the signal to outboard gear, then returning the processed signal to the iD22 and recording it to new tracks (as opposed to using outboard gear on the way in while tracking).

As far as I understand, outboard compressors and EQs need a line-level input signal and their output signals are also line-level. Therefore, the pair of insert send/returns would be ideal since the sends are line-level and the returns completely bypass the iD22's preamps. However, I'd ideally like to own two 2-channel pieces of outboard gear and have them simultaneously patched in at all times (so 4 inputs and outputs needed), BUT I would only ever be using one piece of gear at a time, therefore I would only need 2 simultaneous inputs (and I know the iD22 can only provide A/D conversion for 2 inputs at a time). So, my main questions in this situation are:

If I already have my tracks recorded and I toggle between using Outputs 3/4 and the 2 insert sends in order to send signals to outboard gear, are there any differences between these pairs of outputs when routed through my DAW? They both undergo the same D/A processing and they both output line-level signals, correct?

Although I know only 2 channels of A/D can be used at once, how is it determined which input channels are active if both the main inputs and the insert returns have cables plugged into them simultaneously? Is this something that can be selected in the DAW or is one pair of inputs automatically defeated if cables are plugged into the other pair?

If cables can indeed be plugged into both the main inputs simultaneously and the active inputs can be selected within the DAW with no problems, is there a way to bypass the preamps of the main inputs? If I'm understanding correctly, the main inputs will accommodate line-level signals from TRS cables. Is this just an impedance and gain change, or is the preamp actually bypassed? If it is not bypassed, will the signal be perceptibly colored with the preamp gain so low?

I apologize for the lengthy background information and questions, but I would love to hear from you, as I'm very intrigued by this interface!

The inserts for iD22 are analogue only and sit between the analogue mic pres and the inputs of the ADC digital card. Therefore you cannot address the inserts from the DAW. They are in the input path which you will patch to whilst recording from microphones or LOOPING back signal from spare DAC outputs through the mic/line combi jack inputs.

In order to have 2 stereo hardware processors available, it would be best that you use a small patch panel so that the equipment can be patched into the insert send and return when you are recording via mics/line sources, or alternatively can be patched from DAC3-4 to HARDWARE to ADC returns 1-2. Thus creating what is known as a "hardware insert" from the DAW.

As the insert return is in series with the mic/line input and uses normalling jack connectors, plugging something into the return jack with disconnect the output from the mic pre (available on the insert send jack) and the ADC will be fed from the signal present at the insert return jack. This is typical of any console style insert point.

To this end, it would require some form of normalling in a small patch panel, typically I would suggest half normalling. Which would mirror the functionality of our iD22 insert point, but move it to the patch panel where you can select the appropriate piece of outboard to use.

As previously mentioned, there are only 2 ADC inputs on iD22, so anything connected to the insert return will take over, thus you have to normal wire or connect the output of the mic pre with or without your processing device using a physical cable to the insert return point. This is typical of a "standard insert point".

The insert return is a balanced line input and thus the purist way into the ADC. The mic/line connector runs through the mic preamp circuitry and HPF before feeding the insert send jack. With nothing plugged in here, the signal passes through the send jack, to the return jack and into the ADC.

I hope that helps decipher how the unit works. It would be worth looking at the block diagrams on the website so that you can see the signal flow unfold.